The hemodynamics of erectile dysfunction following external beam radiation for prostate cancer

Introduction. Radiation to the pelvis is associated with erectile dysfunction (ED). The mechanisms include neural injury, vascular alterations, and corporal smooth structural changes. There exists little data on the vascular assessment of men who present with ED following radiation therapy for prostate cancer. This study was conducted to evaluate the erectile hemodynamics in such a patient population. Methods. Men who presented for the evaluation of ED following radiation therapy for prostate cancer underwent vascular evaluation in the form of dynamic infusion cavernosometry and cavernosography (DICC). Established parameters were recorded to define arterial insufficiency and venocclusive function including cavernosal artery occlusion pressure, flow-to-maintain, and pressure decay. Results. Sixteen men with a mean age of 61 years presenting with ED after radiation under-went DICC at a mean duration post radiation of 11 months. All of the patients in whom arterial hemodynamics were measurable had abnormal arterial parameters, and 85% had abnormal venoclusive parameters. Of the patients who could undergo cavernosography, 80% had venous leak, most commonly from the crura. Conclusions. Men presenting with ED following radiation therapy for prostate cancer are likely to have significant alterations in erectile hemodynamics, often of a combined arterio-venogenic nature. In patients with venous leak the majority had venocclusive dysfunction with venous leak emanating from the crura.